The invention is a grounding/positioning clip for positioning matching capacitors relative to a power transistor on input and output substrates. In particular, the clip includes miniature compression mica capacitors attached to the clip by either high temperature soldering or spot welding. The clip is placed over a power transistor cap and soldered to ground plating on the input and output substrates which are associated with the power transistor. The miniature compression mica capacitors are also soldered to plating on the substrates or the transistor leads.
In the prior art, hand placement was employed and hand soldering was used to physically install RF matching capacitors in close proximity to the RF power transistor in a RF device. Proper placement of the RF matching capacitors is critical to the electrical performance of the circuit. Reliable and repeatable proper placement of the RF matching capacitors is critical in any practical commerical product assembly. The inaccuracies inherent in the two hand operation of hand placement and hand soldering, results in suboptimal electrical performance and unsatisfactory yield. Proper circuit operation requires a physically short, low inductance ground path between the input and output circuits of the power amp. In the prior art this was accomplished by two individual ground straps, such as a flat wire conductor or copper connecting wire soldered across the gap between the input and output substrates of the power transistor. The prior art method of creating a ground path between the input and output circuits was labor intensive since it involved the hand soldering of ground straps of some type. A DC ground return path must also be provided for proper circuit operation of the power transistor circuit. Traditionally, this DC ground path was provided by a buss bar or a printed circuit board trace. The invention eliminates the need for a buss bar or printed circuit board trace by permitting the use of the chassis or heatsink as a DC ground connection via the body of the positioning clip. The invention thereby reduces labor and cost since no separate DC ground connection is required.
It is the object of this invention to provide an RF power transistor clip with preassembled capacitors which repeatably are locatable in their proper physical placement for proper RF matching.
It is a further object of the invention to eliminate the considerable hand labor needed during circuitry assembly of a RF power transistor circuit while providing a physically short low inductance ground connection between the input and output circuit substrates of the power transistor and a DC ground return path.